In commercially available guarding devices, when a burglar tries to break in a protected premise, the burglar actuates an alarm signal on the alarm control panel. This alarm may be actuated by other means (e.g., a "panic button"). The signal is sent to a central station (hereinafter called CS), such as a police station or a post of a guarding station. However, this is not always sufficient in view of the high rate of false alarms. Thus very often one or more additional operations are optionally required, which are not met by the current art, as such:
a. audio verification of the alarm; PA1 b. acoustic detection of the alarm; PA1 c. a "stored audio" feature enabling the CS operator to listen-in, for a predetermined period of time, to the recording of the sounds prior to the alarm activation in addition to the real-time audio (option a); PA1 d. a two-way speech (i.e., enabling talking between the CS operator and the person(s) being in the protected premise); and PA1 e. video verification of the alarm.
There is known a device which can be used for some of the above possibilities. However, the existing device cannot be connected to any of the standard alarm control panels, but requires a special one.
It has thus been desirable to design a device which can be connected to any standard alarm control panel and, if desired, to be adapted to all the possibilities.